strengthes of gradethis over testwhat from datacamp

As there has been an API function testwhat_learner() in testwhat for learnr and testwhat has provided us a full set of functions to check exercises, then what's the benefit to reinvent the wheel? or what are the designed strengths of gradethis over testwhat? :grinning:

I just need some courage for switching from testwhat to gradethis. :thinking: